Fluid actuated drill feed



Feb. 5, 1935.

FLUID ACTUATED, DRILL FEED Filed Dec. 4, 1930 A. M. s'osA 1,990,052?" 55Sheets-Sheet l wuent oz I WWW Feb. 5, 1935.

'A. M. sosA 1,990,052

FLUID ACTUATED DRILL FEED- Filed Dec. 4, 1930 5 Sheets-Sheet 2 avweutozFeb.5,1935., AI.NII.SOSA 1,990,052

FLUID ACTUATED DRILL FEED I Filed pe. 4, 1930 3 Sheets-Sheet 3 awuemtozPatented Feb. 5, 1935 I FLUID ACTUATED DRILL FEED Augustus M. Sosa,Cincinnati, Ohio, assignor to The Cincinnati Bickford Tool Company,Cincinnati, Ohio, a corporation of Ohio Application December 4, 1930,Serial No. 500,005

,11 Claims.

' Vance or movement of the machine element is controlled by the rate atwhich fluid is permitted to be discharged from the exhaust side of themotor.

It has for its main object to provide an hydraulic circuit capable ofutilizing a standard .make gear pump for effecting the feeding andtraversing movements of the machine element in place of the relativelymore expensive types of pump units, such as, for example, pumps. of thereciprocating piston type.

Another object of this invention is to provide a system wherein thedischarge from the pump may run pressure free or substantially so, tothe reservoir at all times except during feeding movements, thereby torelieve the load upon the pump and its driving means and thus preventunnecessary heating of the oil and undue wear upon the parts. And as anadditional refinement to provide a means for automatically bypassingafraction of or all of the supply fluid whenever the pressure in thesupply line tends to exceed a predetermined maximum.

Still a further object of this invention is to provide an hydraulicsystem with but few opcrating parts easily constructed an d assembled,for selectively imparting feeding and traversing movements to a machineelement.

In the attainment of the objects of this invention, I propose to use aconstantly driven gear pump for providing the desired pressures andflows and pass substantiallythe entire discharge therefrom to thehydraulic motor, through a system of conduits, and to locate a needlevalve or throttle in series with the motor. In

order to avoid all possibility of excessive pressures arising in thesystem an adjustable relief valve is placed in the supply line to permitan outflow therefrom whenever the pressure exceeds a preselectedmaximum. The valves and conduits are so constructed and arranged thatthe movement, whethermanually or automatically,

of one of the valves from one position to another,

(Cl. Gil-52) form, preferably positioned in a motor discharge line, forcontrolling the rate of movement of the carrier, and effective only whenthe valves are positioned for effecting a feeding rate of movement.

Other objects and advantages will be in part indicated in the followingdescription and in part rendered apparent therefrom in connection withthe annexed drawings.

To enable others skilled in the art so fully to apprehend the underlyingfeatures hereof that they may embody the same in the various wayscontemplated by this invention, drawings depicting a preferred typicalconstruction have been annexed as a part of this disclosure and, in suchdrawings, like characters of reference. denote corresponding partsthroughout all the views, of which:

Figure 1 illustrates an embodiment of this invention as applied to adrilling machine, the parts being arranged to effect a traversingmovement to a sliding carriage. Fig. 2 is a similar diagram but with theparts arranged for effecti'ng aslow movement or feeding movement'to thecarrier. Fig. 3 is a diagram illustrating the parts in a position foreffecting a return movement of the carrier. Fig. 4 diagrammaticallyillustrates the parts-positioned to eflect a rapid traverse movement ofthe carrier.

Referring more particularly to Fig. 1 the hydraulic motor M isoperatively connected with a sliding -tool carriage S, as by means ofthe piston rod 5, but it is to be understood, however, that eitherelement of the motor may be connected with the work carrier or toolcarrier as the installation requires. In this particular application thetool T is rotated by means of the gears 6, one of which has a splinedconnection with the spindle '7 journaled in the support S which ismounted for translation upon the bed or frame F of the machine.

Propulsion of the support Sis effected hydraulically, the pressure fluidbeing supplied by a pump P, driven from a shaft 4, which urges the fluidthrough line 10 to a point a where it branches, one branch 11 leading tothe reservoir R and another branch 12 leading to a direction controlvalve B. With the valve in the position b illustrated in Fig. 1, fluidis directed through conduit 13 to the large end of the cylinder m andurges the piston m and parts connected there- I with forwardly. At thesame time fluid is dis-' charged from the small end of the cylinder"through lines 21 and 14, valve A (which for a traversing movement isopen or in the position a) and line 15 to the pump and reservoir; thesupport S is thereby caused to be moved at a traverse rate.

When the workpiece is reached, valve A is moved to the position a"either manually or by suitable trip mechanism operated by the carriage,to cut off the free discharge to the reservoir. The motor discharge thenpasses through exhaust line 15 to a valve C, which, in the positionillustrated in Fig. 2, directs the fluid through discharge line 16 to aserially arranged variable resistance element D and thence to dischargelines 17 and 18 to the reservoir.

The rate or velocity of flow through the throttle D and thus the rate ofadvance of the carrier S, is determined by the setting of the throttlingmember d. With such a system there will always be a greater pressure inthe forward pressure line, if there is to be any movement of the carrierat all, than in the back pressure line and, during the toolingoperations, the throttle D limits the rate of, discharge and causes aback pressure of a value sufficient to prevent a jumping of the carrierwhen the value of the work resistance changes.

If the conditions of operation are such that-a rapid traverse movementis required, as for example, to shortenthe distance between tool andwork and before engaging the work the valve C may be first moved to theposition 0' (indicated by the dotted lines in Fig.2), connecting exhaustI line 15 with line 19 and the large end of the cylinder. Both ends ofthe cylinder are then under pressure but due to the differential in theeffective areas of the piston m, the carrier S will be moved forward asbefore but at an increased rate and with a consequent reduction inpower. When tool and work are in close proximity the valves may betripped as above explained, to effect, if. desired, an intermediatetraverse rate followed by the feed rate or toefl'ect a feed rate alone.

Or if the valve C be turned to the position indicated by the referencecharacter c", the fluid passes from line 13 directly to exhaust line 19,

valve C, and discharge line 20 back to the reservoir R and the head 8comes to rest, the throttle D being thus cut out of the circuit at thistime.

For effecting a traverse movementin the opposite direction,"as forexample, at the completion 'of the drilling operation, the directioncontrol valve .3 is moved to the position b (Fig. 3). Pressure 'fluid isthen directed through lines 14 and 21 to the small end of the cylinderand' the fluid discharged from the large end is passed through line 19to the rate, and direction control valve C and thence through lines20and f8 tothe reservoir. The outflow from the motor being unrestricted,the carriage Sis caused to return at a rapid rate. The travel of thecarrier may be suspended at the completion of its stroke or at any timeduring the return movement by adjusting the rate valve A so as to passthe pressure fluid directly to the reservoir through the line 15. Thusit will be seen that the travel of the carrier may be stopped at anypoint in its travel, and the pressure in the system and the load uponthe pump immediately reduced to a minimum, merely by the opening eitherof the valves A or C to the reservoir.

Obviously various other cycles of movement may be imparted to thecarrier by varying the sequence or order of movement ofthe valves. For

thereby trapping the fluid in the discharge end of the motor and openingthe intake end to thement in either direction, the valve mechanisms maybe moved to intermediate positions to block all flow of fluid to andfrom the motor. Under these conditions, the supply fluid. will then bepassed through a pressure control element 25:

As an additional refinement, this invention proposes a means I forguarding against excessive stresses or damage to the tool or work in theevent that the carrier S meets an obstruction, or, to prevent thepressure inthe forward pressure line of the system from exceeding apredetermined value however caused, the pressure controller 25,adjustable to suit requirements, is inserted in the pump outflow branchline 11. forward pressure exceeds a preselected maximum, as for example,by reason of an increase in the work resistance, the valve 25 opens andby-passes the excess fluid to the reservoir; Likewise, in the Thus, whenthe" event that the carrier S or tool T meets an obstruction, theby-pass valve opens and further travel of the carrier is suspended. Anadjusting screw 26 is provided for varying the effectiveness of thespring 27 to increase or decrease the pressure required to open therelief line to the reservoir.

Without further analysis, the foregoing will s fully reveal the gistofthis invention that others can, by applying current knowledge, readilyadapt it for various utilizations by retaining one or more of thefeatures that, from the standpoint of the prior art, fairly constituteessential characteristics ofeither the generic or specific aspects ofthis invention and, therefore, such adaptations should be; and areintended to be, comprehended within the meaning and range of equivalencyof the following claims.

Having thus revealed this invention, I claim as new and desire to securethe following combinations and elements, or equivalents thereof, by

Letters Patent of United States:

' 1. An hydraulic system combining an hydraulic motorM; a reservoir R; agear pump P for supplying fluid under pressure to said motor; aconsecond control valve, or through saidsecond valve I directly to saidreservoir.

2. An hydraulic transmission of the discharge regulated type combiningan hydraulic motor having a cylinder and a piston of the differentialtype; a pump for supplying fluid to said motor; a reservoir; fluidconduits and valve means for with said pump and auxiliary valve meansfor selectively connecting either end of said motor with said reservoiror both ends of said motor together so constructed and arranged that fora given setting of the auxiliary valve. means the discharge from themotor during a forward stroke passes to the reservoir to effect a givenrate alternatively connecting either end of said motor of movementthereof and for another setting of said valve means the discharge fromsaid motor during a forward stroke augments .the quantity supplied bythe pump to the other end of the intake side of said motor and a motordischarge conduit connected with the opposite side thereof; a pump forsupplying fluid to said motor; a variable resistance element in saiddischarge conduit; valve means in said discharge conduit between saidresistance element and said. motor, said valve means also beingconnected with the intake side. of said motor; and means for selectivelypositioning said valve means to direct the motor discharge fluid throughsaid'resistance element or to the intake side of said motor.

4. A machine tool combining a translatable carriage; means for efiectingtranslation of said carriage, said means including an hydraulic motorconnected with said carriage and provided at one end with an intakeconduit and at its opposite end with two discharge conduits, one of said.discharge conduitsbeing normally open; a source oi fluid under pressureconnected with said intake conduit; means located in one of said dis-'charge conduits for controlling the rate of flow therethrough thereby tocontrol the rate of movement of said motor; and valve means fordirecting the fluid discharged from said motor selectively through saiddischarge conduits.

5. An hydraulic system including a reversible difierential hydraulicmotor; a pump for supplying fluid under pressure to said motor; a systemof conduits for conveying fluid to and from said pump and motorincluding a first normally open motor discharge 'conduit and a secondconduit having therein a normally fixed resistance, said first dischargeconduit aiiording an unrestricted passage for the discharge fluid; aseries of valves for controlling the action of said motor including astop valve in said normally open conduit, adirection control valve inthe conduit connected 'with the intake side of said motor and a selectorvalve connected with said second discharge conduit and operative whensaid stop valve is closed to permit fluid discharged from said motor topass through said second discharge conduit or to direct it into theintake side of said motor; and means for actuating said valves.

' 6. An hydraulic system for machine tools combining a differentialreciprocating motor; a pump and suitable conduits for supplyingactuating fluid to said. motor; a valve in said conduits for selectivelydirecting the actuating fluid to either end of said motor; an exhaustconduit connected with each end of said motor; a rate selector valveconnected with each of said exhaust conduits; a discharge line connectedwith said rate selector valve; a throttlein said discharge line for re,stricting the flow of fluid therethrough; and means for-selectivelyshiftingv said late selector valve to one position in which-it connectssaid exhaust conduits thereby to permit the fluid discharged from oneend of the motor to enter the opposite end of the motor and combine withthe actuating fluid to effect rapid actuation of the motor or to anotherposition in which it' connects one of the exhaust conduits with saiddischarge conduit thereby to 'efiect slow actuation of said motor underthe influence of the actuating fluid.

7. A machine tool combining a translatable carriage; means for cflectingreciprocations of said carriage said means including a reversiblehydraulicmotor connected with said carriage and provided at each endwith independent intake and exhaust ports; a source of fluid pressure; adirection control valve and suitable conduits for connecting said sourceselectively with the intake ports of said motor; a discharge conduitconnected with each of said exhaust ports, one 0! said dischargeconduits being normally opento permit unobstructed flow of fluidtherethrough when said motor is operated in one direction; means in the7 other discharge conduit for controlling the rate of flowtherethroughthereby to control the rate of movement of the motor in the oppositedirection; and other valve means, independent of said direction controlvalve, connected with said discharge conduits and adapted to render,said open 8. An hydraulic system including a reversible differentialhydraulic motor; a pump for supplying fluid under pressure to saidmotor; a system of conduits for conveying fluid to and from said pumpand motor including a first normally open discharge conduit and a seconddischarge conduit having therein a normally fixed resistance, said openconduit affording an unrestricted passage for the discharged fluidduring rapid actuation of said motor; a series of valve mechanisms forcontrolling the action of said motor including a direction controlvalvelocated in the conduit connected with the intake side of saidmotor; a selector valve in the motor discharge conduits operative todirect the motor discharge fluid to said first discharge conduit duringmovement of said motor in one direction, and selectively through saidsecond discharge conduit or to the intake side of said motor duringmovement of said motor in the opposite direction; and means foractuating said valves.

9. An hydraulic circuit combining an hydraulic .motor of the cylinderand piston type; a source of fluid pressure adapted to be connectedselectively with the opposite ends of said motor to actuate said motorin forward and reverse direc-' tions; an exhaust conduit connected witheach end of said motor; a valve connected with both of said exhaustconduits; two discharge conduits connected with said valve, one of saiddischarge conduits being normally open and aflording an unobstructedflow for the discharged fluid thereby to effect rapid actuation of saidmotor; and a throttleyalve in the other of said discharge conduits toefiecta reduced rate of actuation of said motor; the first mentionedvalve being adapted to connect one of said exhaust conduits with thenormally open discharge conduit during'actuation of said motor in onedirection and with the other discharge conduit during actuation of themotor '01 said motor; exhaust conduits connected with the opposite endsof said motor; a control valve connected with both of said exhaustconduits;

V first and second discharge conduits connected with said control valve,said first discharge conduit afiording an unrestricted passage for fluiddischarged by saidmotor when actuated in one direction; a throttle valvein said second discharge conduit adapted to restrict the flow of fluidtherethrough during actuation of the motor in the opposite directionthereby to reduce the rate of movement of said motor; and means to shiftsaid control valve to a position to connect one of said each end of saidmotor; two discharge conduits adapted to be connected with said exhaustconduits respectively one of said discharge conduits being normallyopen, a throttle device in the other of said discharge conduits torestrict the flow of discharged fluid therethrough; and a valve con-'nected with both of said exhaust conduits and;

with both of said discharge conduits, said valve being adaptedselectively to connect one of said exhaust conduits with said normallyopen discharge conduit to effect relatively rapid actuation of saidmotor in one direction'or to connect the other of said exhaust conduitswith the other of said discharge conduits thereby to eflect relativelyslow actuation of the motor in the opposite direction or to connecttogether said 'two exhaust conduits to connect the discharge end of themotor with the intake end thereof, thereby to effect actuation of themotor at a rate higher than said rapid rate.

AUGusTos M. sosa. 2o

